Grease and lubricant



Patented May 19, 1942 cause AND nunmciwr George W. Fiero, Buffalm N. Y.

No Drawing. Application-January 9, 1940, l 7 Serial No. 313,042.

18 Claims. ((1252-31) them being that greases prepared from suchaluminum soaps are highly transparent, waterproof and stable to heat.These greases are ordinarily manufactured by heating an aluminum soapofa higher saturated fatty acid with a mineral oil such as a heavyparafiin oil, and then permitting the gel to cool whereby the mass setsto form a grease. While this method of manufacture is in most caseseminently satisfactory, occasionally greases are obtained which tend tobleed; i. e. the greases are not stable, the solvent tending to separatefrom the gel. Many attempts have been made to remedy this difficulty,but as yet no satisfactory method has been found for insuring theproduction of'non-bleeding aluminum soap greases.

It is an object of this invention to provide a process for thepreparation of non-bleeding greases comprising aluminum soaps of highersaturated fatty acids.

I have found that greases comprising aluminum soaps of higher saturatedfatty acids and relatively small amounts of a substance selected fromthe group consisting of hydrogenated castor oil and the fatty acidsobtained therefrom show markedly reduced tendencies toward bleeding, ascompared with ordinary greases containing aluminum soaps of highersaturated fatty acids.

Such greases may be prepared by dissolving hydrogenated castor oil, orthe fatty acids ob-' .40.

tainedtherefrom in the oil in which the aluminum soap is dissolved inorder to form the grease]; thus, for example, the greases of myinvention may be manufactured by heating a relatively small amount of asubstance selected from the 4 above group and an aluminum soap of ahigher saturated fatty acid with a mineral oil to elevated temperatures,and then permitting the mass to cool soas to form the grease. Myinvention also permits the production of substantially nonbleedingaluminum-soda soap greases: this feature of my invention is mostsurprising, since soda soap greases normally have a marked tendency tobleed and hence are somewhat unsuitable for bleeding aluminum-soda soapgreases maybe prepared in accordance withmy invention isalso importantbecause'of the fact that such greases are cheaper than the:'corresponding aluminum soap greases, and hence may be more widely usedfor commercial purposes. The hydrogenated castor oil employed inaccordance with" my invention'may be easily prepared by subjectingcastor oil'to catalytic hydrogenation. I prefer to employ hydrogenatedcastor oil having an iodine valueless than about 30. The fatty acids ofthehydr'ogenated; castor oil may be obtained in the ordinary manner bysaponifying the hydrogenated castor oil with alkali or by any othermeans known to the art: these fatty acids comprise chiefiy IZ-hydioxystearic acid. Soaps of these fatty acids may'also be employed inaccordance with my invention although I prefer to employ eitherthe oilor its fattyacids." v

The greases of my invention may beprepared in substantiallythe'samemanner' a's ordinary aluminum soap; greases are -prepare'd.Thus; for example, a mixture of aluminum stearate and/or aluminumpalmitate and either hydrogenated castor oil or the fatty acids obtainedtherefrom may be heated with an 'oil 'and'the mass then cooled to formthe'grease.* I'he oil employed may be any oil suitable forthepreparation of greases; for example, paraffln base oils-,asphalt baseoils or naphthenic bas'eoils may be employed, depending upon the type ofgrease it'isdesired to prepare. The amountfof aluminum soap of thehigher 'saturatedfatty acid heated with the oil grease desiredgenerallyit is suitable toprepare a grease containing about 10%-"more or less-'of the aluminum'scap; The amount of hydrogenated castor onorhydrogenate'd castor "oil fatty'acids heated'withthe'oil may likewisevary somewhat, but ordinarily a grease containingbetweerr'about 05% andabout 10% 'of these products, the particular amount varying with thealuminum soapcontent of the grease, possesses the desiredcharacteristicsc In order toform the grease'the: above mixture may beheated to .elevateditemperaitures, e. g. temperatures varying betweenabout 275 F. and about .300'F.,- and the massthenpermitted-to coolin-orderto formthe grease. Pref erablythe cooling is carried out rathercarefully in order-to obtaina uniform grease, as is well known to greasemakers. In practically every case I vhav'e -i'oundthat the greasespreparedin accordance with my invention "show notendenc'y general use.The fact that substantially non; toward bleeding,'whereas similargreases-containthereof in many cases show pronounced bleeds.

An importantfeature of my invention involves the preparation ofaluminum-soda soap. greases which are substantially non-bleeding. Asabove pointed out, it has long been recognized that because of thecomparative cheapness of soda soaps, it would be desirable to employgreases containing these soaps for many commercial purposes; as yet,however, the tendency of greases containing these soaps to bleed hasprevented their extensive use. The aluminum-soda soap greases of myinvention are suitably prepared by heating a mixture of an aluminum soapof a higher saturated fatty acid, a sodium soap of a higher saturatedfatty acid and either hydrogenated castor oil or the fatty acidsobtained therefrom with an oil, and then permitting the mass to cool soas to form the grease. amount of aluminum soap and soda soap heated withthe oil may vary widely depending upon the type of grease it is desiredto prepare; I have found, however, that greases containing anywhere fromabout 1% to about of each of these soaps, when prepared in accordancewith my invention, are highly suitable. The

, aaaaeoa ing no hydrogenated castor oil or fatty acids ated fish oilhaving an iodine value less than 10 and 4 parts of aluminum stearatewere mixed with 90 parts of an asphalt base oil having a amount ofhydrogenated castor oil or its fatty acids incorporated in thegreases'of my invention may likewise vary, but ordinarily an amountvarying between about 0.5% and about 10%, the particular amount varyingwith the soap content of the grease, is suitable in order to preparethese non-bleeding greases. The method of preparing these greases issubstantially the same as that described in connection with thepreparation of the aluminum soap greases, except that the temperature towhich the mixture'is heated should preferably be between about 450 F.and about 500 F.

I have made the observation that heating hydrogenated castor oil or itsfatty acids with mineral oils causes a thickening of these oils. Thisphenomenon may be utilized, if desired, in order to prepare thickenedmineral oils for various purposes. The ability of the substances used inaccordance with my invention to thicken mineral oils upon being heatedtherewith may explain the surprising improvements in the greasesprepared in accordance with my invention; however, I do not wish to beconfined to any particular theory with regard to the manner in which myinvention operates.

The following examples are illustrative of the greases which may beprepared in accordance with my invention; amounts are given in parts byweight.

Example I '10 parts of aluminum stearate and 90 parts of the sameparaflin oil produced a noticeable bleed.

Example II 2 parts of the fatty acids obtained by saponifyinghydrogenated castor oil having an iodine value of 2.7, 4 parts of a sodasoap of hydrogen- Saybolt viscosity of 300 seconds at F. This mixturewas then heated to 480 F. and permitted to cool slowly to roomtemperature. The product obtained was av transparent, uniform, softgrease which showed no tendency toward bleeding. A grease prepared inthe same manner and containing no hydrogenated castor oil fatty acidsshowed a noticeable bleed.

Example III 1 part of the fatty acids of hydrogenated castor oil havingan iodine value of 2.7, 2 parts of the soda soap of a hydrogenated fishoil having genated castor oil fatty acids showed a noticeable bleed.

It will be evident from the above description that my invention permitsthe production of greases containing aluminum soaps of higher saturatedfatty acids and of greases containing both aluminum and soda soaps ofhigher saturated fatty acids, which greases have substantially notendency toward bleeding. Hence it will be evident that my inventionwill be of great interest to those engaged in the manufacture oflubricants and greases.

Since certain changes in carrying out the above processes and certainmodifications in the compositions which embody the invention may be madewithout departing from its scope, it is intended that all mattercontained in the above description shall be interpreted as illustrativeand not in a limiting sense.

Having described my invention, what I claim as new and desire to secureby Letters Patent is:

1. A grease comprising an aluminum soap of a higher saturated fattyacid, a mineral oil and a relatively small amount of a substanceselected from the group consisting of hydrogenated castor oil andlz-hydroxy stearic acid.

2. A grease comprising an aluminum soap of a higher saturated fattyacid, a mineral oil and a relatively small amount of hydrogenated castoroil.

3. A grease comprising an aluminum soap of a higher saturated fattyacid, a mineral oil and a relatively small amount of 12-hydroxy stearicacid.

4. A grease comprising aluminum stearate, a mineral oil and betweenabout 0.5% and about 10% oi hydrogenated castor oil having an iodinevalue less than about 30.

5. A grease comprising aluminum stearate, a mineral oil and betweenabout 0.5% and about 10% of 12-hydroxy stearic acid.

6. A grease comprising an aluminum soap of a higher saturated fattyacid, a soda soap of a higher saturated fatty acid, a mineral'oil and arelatively small amount of a substance selected from the groupconsisting of hydrogenated castor oil and l2-hydroxy stearic acid.

7. A grease comprising an aluminum soap of a higher saturated fattyacid, a soda soap of a higher saturated fatty acid, a mineral oil and arelatively small amount of hydrogenated castor oil.

8. A grease comprising an aluminum soap of a higher saturated fattyacid, a soda soap of a higher saturated fatty acid, a mineral oil and arelatively small amount of 12-hydroxy stearic acid.

9. A grease comprising aluminum stearate, a soda soap of a highersaturated fatty acid, a mineral oil and between about 0.5% and about 10%of hydrogenated castor oil having an iodine value less than about 30.

10. A grease comprising aluminum stearate, a soda soap of a highersaturated fatty acid, a mineral oil and between about 0.5% and about10%of 12-hydroxy stearic acid.

11. A grease base comprising an aluminum soap of a higher saturatedfatty acid and a substance selected from the group consisting ofhydrogen ated castor oil and 12-hydroxy stearic acid.

12. A grease base comprising an aluminum soap of a higher saturatedfatty acid and hydrogenated castor oil;

13. A grease base comprising an aluminum soap of a highersaturated-fatty acid and12-hydroxy stearic acid. I

14. 'A grease base comprising aluminum stearate and hydrogenated castoroil having an iodine value less'than about 30.

15. A grease base comprising aluminum stearate and 12-hydroxy stearicacid.

16. A grease base comprising an aluminum soap of a higher saturatedfatty acid, a sodium soap of a higher saturated fatty acid and asubstance selected from the group consisting of hydrogenated castor oiland 12-hydroxy stearic acid.

17. A grease base comprising aluminum stearate, a soda soap of a highersaturated fatty acid and hydrogenated castor oil having an iodine valueless than about 30.

18. A grease base comprising aluminum stearate, a soda soap of a highersaturated'fatty acid and 12-hydroxy stearic acid.

GEORGE w. HERO.-

